A nitride semiconductor light emitting device includes first and second type nitride semiconductor layers. An active layer is disposed between the first and second type nitride semiconductor layers. A current spreading layer is disposed between the second type nitride semiconductor layer and the active layer. The current spreading layer includes first nitride thin films and second nitride thin films which are alternately laminated. The first nitride thin films have band gaps larger than those of the second nitride thin films. A first plurality of first nitride thin films are positioned at outer first and second sides of the current spreading layer. The first plurality of first nitride thin films have a thickness greater than that of a second plurality of first nitride thin films positioned between the first plurality of first nitride thin films.